Inflatable boat bottom



Jan. 23, 1945. J. G. KREYER INFLATABLE BOAT BOTTOM Filed Jan. 21, 1943 Patented Jan. 23, 1945 INFLATABLE BOAT BOTToM John G. Kreyer, Akron, Ohio, assignor to The Firestone Tire & Rubber Company, Akron, hio, a corporation of Ohio Application January 21, 1943, Serial No. 473,137

i claim.

This invention relates to inflatable boats and more especially it relates to an independently inatable boat ioor which is adapted to be used as a raft in the event a boat of which it is a part should become submerged.

Applicant, is aware of inflatable boat construction such as disclosed by the William Williams Patent No. 31,948 dated January 1, 1861 vwherein is disclosed the forming of tubular' members composed of India rubber, arranging the tubes in side by side relation and lashing them together, closing the ends of the tubes against air leaks, installing an inflation valve in the walls of the air chambers and inflating the chambers whereby a soft mattress is formed which may be used as a raft. The patent iurther discloses that by applying inated gunwales to the mattress or raft that a scow may be made. Such gunwales were to be made of inatable tubular members after the fashion of the mattress.

Applicant also is aware of the disclosures of the Hiram Douglas Layman et al. Patent No. 19,769 (British) dated 1898, wherein is disclosed an inflatable boat composed of rubberized fabric in which both the sides and the iioor have air chambers. The Layman et al. patent further discloses means for attaching propelling 'means and a rudder to the outer surface of the side and stern of the rubber boat. Layman also discloses means for erecting a mast in his boat which mast extends completely through the bottom of the boat. Furthermore, as he discloses, the installing in an inflatable rubber boat of a gunwale or break-water, as well as a center board for sailing.

Applicant also is aware that it is obvious that the inflatable rubberized fabric surf board of R. Hopkinson Patent No. 1,671,642, dated May 29, 1928, is or could be made suitable for use as a removable, or auxiliary rubber boat bottom. Also that Anderson, Patent No. 1,891,492, dated December 20, 1932, discloses a cellular inflatable member of rubberized fabric for an inflatable rubber boat which holds the boat to shape and is detachable from the boat in which detached condition it may be used as a life preserver, presumably in the manner of a life raft.

Although the field of inflatable boats has been quite thoroughly developed yet the prior art does not disclose an inatable boat formed of tubular air compartments wherein the end construction of the tubes is so formed and rein- ,fo-rced as to insure a permanent air-tight seal. 'Such a construction and the method of making "the same is important since the area to be vISIS cemented and vulcanized together in a single boat is very large and the-operation heretofore has been difficult to perform thereby increasing the chances of ra leak from defective workmanship.

An object of the present invention is to provide a removable iniiatable oor for a boat having a multiplicity of separate elongated closed air chambers whose ends are strong and formed in a manner which unskilled workmen can prefabricate without the danger of the said chambers leaking when the floor is used as a raft.

Another object is to provide an inflatable iioor for a boat which floor cannot, when in service, be completely deflated by horizontal gun re and `that will require a multiplicity of hits by gun fire from an airplane above to deflate it.

The foregoing and other objects, features and advantages of the invention will be understood by those familiar with the art from the following description in conjunction with the accompanying drawing wherein the invention has been shown by way of examplefand wherein;

Fig. 1 isa top plan view of a boat floor embodying the present invention shown with the side and top cover partially removed in order to illustrate more clearly the construction of the bulkheads;

Fig. 2 is a side elevation of Fig. 1 illustrating the relative position of the side frame, the permanent boat oor, and the detachable auxiliary :door

Fig. 3 is an enlarged sectional View taken on line 3 3 of Fig. 1 showing the construction of an end of one of the bulkheads at one stage of its manufacture;

Fig. 4 shows the same structure as Fig. 3, at more advanced stage of manufacture;

Fig. 5 is an enlarged sectional View taken on line 5 5 of Fig. 1 showing the construction of the end of a iinished bulkhead relatively to 'the sides of the oor; and

Fig. 6 is a sectional view taken on line 6 6 of Fig. 1 showing the partition walls separating two groups of bulkheads, and alsoI showing the walls and communicating chambers of a bullahead within a single group.

4seen by reference to Fig; l that the peripherial outline of said floor' ID is generally that of the bottom of a boat and that said tubes are arranged in four separate groups, namely, W, X, Y, and Z, with a, b, c, d, e and f constituting group W; g, h, i, :i and k group X; l, m, n, o and p, group Y; q, r, s, t, u, and v, group Z. The construction of the individual tubes is substantially the same and will now be described by Way of example, in connection with tube u and i in the stage of construction shown in Fig, l. The walls of all the tubes are composed of rubberized fabric of a type that is light in weight and thickness and is impervious to air or other common inflating gas. The tubes are built to substantially rectangular form by wrapping the rubberized fabric about an elongated transversely rectangular form, overlapping the edges of the fabric in the manner commonly used in the rolling operation in manufacturing pole inner tubes, as will be understood by those familiar with the art. After the overlap has been made the rubberized fabric is stripped endwise fromthe form. It has been found that in an uninflated condition the tube thus formed retains substantially the' transversely rectangular shape of the building form. Obviously the tubes could be formed ina number of ways without departing from the spirit of the invention. Thus the tubes may be molded in the manner of molded inner tubes, or they may be cross-wrapped on forms and vulcanized or molded similar to garden hose, and such' modifications are within the concept of the invention. Next, communicating holes, `I I, throughr which air 0r other inflating medium may flow, are. punched out or otherwise cut in the vertical side walls of the rectangular tubes. 'I'hese holes` may be approximately in diameter, and theirv purpose and location will presently be explained. As illustrated in Fig. 3 the. end portions I2, I2 of the tubes are. shown pressed together and: then turned or folded back on themselves after which a rubberized strip of tape. I5 isy folded over the folded edges of the endy portionsv of the tubes, care being taken during' these operations: tov stitch the folds firmly together so` that` an air-tight seal is formed.

The other tubes a, b, c, d, e, I, g h, 7', k, 1,. m, n., o, p, q, r, s', t and 'u are manufactured in the same manner as just described inthe making of the tubes u and i. The vertical sides. of all the tubes are cemented and' after the cement has dried the tubes are laid with their cemented sides in abutted relation as shown in Fig. 1 the longest tubes lc and Zfbeing, in the: center. with the successive tubes toward each side being progressively shorter. The cemented sides are pressed firmly together causing the sides to be retained in contact by the tacky nature of the cement, and accordingly the assembled; tubes form` a, smooth flat platform of air-tight tubes. However, the tubes within any one. group, have communicating holes I I formed throughtheir side walls. To have these holes form openings they arel punchedv or cut through the walls of the tubes at predetermined positions, so that when the tubes are assembled in the said floor the. holes I Iy will be aligned (see Fig. 6). Thus it will beseen that although holes I I provide openings between all. thel tubes within one group, to form a group, as for example, group X, the outside tubes g and k of the group X do not have holes II punched in their outside side walls; thus while all the tubes of group X communicate with each other through holes I I, they are closed off from the tubesin all other groups. In similar fashion the groups W, Y, and Z consist lof. a series of tubesv with communicating openings between the tubes within each group, but without communicating holes with the tubes of any other group.

Next the top and bottom surfaces of the assembled tubes are cemented with a coat of vulcanizable rubber cement. After the cement has dried, a top cover I3 and a bottom cover I4 are laid over the entire top and bottom surfaces of the assembly. These covers are rolled down firmly against the cemented surface of the tubes with each cover over-lying the assembled tubes so that when the edge of the bottom cover I4 is turned up around the said tubes and the edge of the top cover I3 is turned down about the tubes, the edges of the said covers meet or are separated only by a short distance. After the covers I3 and I4 have been laid against said assembled tubes, the folded ends of all the tubes are tucked back. (See Fig. 4.) Due to the flexible nature of the material composing the tubes the closed or folded ends may be tucked into the tube so as to cause the new end of the tube, formed by the tucking operation, to extend obliquely of the axis of the tube. Of course the ends of the tubes may, if desired, be trimmed on a predetermined angle before they are assembled. After the ends of the tubes have been tucked back a cemented channelled shape strip I6 of rubberized fabric is positioned as shown in Fig. 4, after which the extending edges ofcovers I3 and I4. are turned down and up, respectively and carry the legs I'I and I8, respectively, with them. Next a reinforcing strip I9, also cemented and of the same material as strip I6, is laid over substantially the entire width of the edge of the tubes after which the upper and lower edge corners are reinforced by cemented strips of tape 20 and 2I, respectively. Next an additional edge strip 22 of the same material as that of the strips described above, is cemented and laid against the edges of the assembly to re-v inforce and to finish the edge of the said auxiliary floor.

In order that each group of tubes, namely, groups W, X, Y, and Z may be inflated, a suitable hole is punched through the top cover I3 and the upper wall of one tube of each group, as for example, the upper Walls of tubes e, i, n and r of groups W. X, Y and Z, respectively, and pillow valves 23, 24, 25 and 28 are installed by any conventional manner found satisfactory. For convenience in handling, lifting straps 2l, 28, 29 and 3D are attached to the upper cover of the door I0. These strips may be of the same material as that of the floor covers and may be attached by cementing.

. The next operation is that of vulcanizing the composite assembly composing the floor. This vulcanization may be accomplished in any one of several ways well known to the art, as for example, `but without limitation, the floor I0 mw be laid in an open steam heat and subjected to a temperature of approximately 300 F. If the open steam vulcanization is used the connections through the valves 23, 24, 25 and 26 must be maintained so that the internal Ipressure within the groups of tubes W, X, Y, and Z may be controlled, which may be done in any conventional manner, in order that the tubes will not be collapsed due to external steam pressure, or be bulged due to the air within the tubes becoming heated and the internal pressure built higher than the external pressure. This latter condition could happen at the end of the vulcanizing operation when the steam pressure would be dropped' before the air in the tubes cooled down 1t is te be understood that the rubberized fabric, of which said boat floor is b uilt, may be vulcanized before it is built into the boat, in which case the nal vulcanization may be effected at a temperature only high enough to vulcanize the rubber cement.

After vulcanization the floor is ready for installation in a boat which is done by simply laying the oor I c in a rubber boat on the regular boat oor. (See Fig, 2.) It lwill now be seen that the inventionprovides an inflatable boat floor which in service lies below the water line of the boat and is therefore protected from shore gun hre.

It will also be seen that the flo-or Hl acts as an auxiliary floor to the regular floor of an inatable boat and that it is separable therefrom, so that in the event a boat, in which said auxiliary floor is used, should sink the auxiliary floor will become a raft to which the occupants of the boat may cling. If it is desired that the auxiliary floor be a more buoyant raft than it is only necessary to increase the depth of the air chambers in the floor. As such depth increases the floor becomes more exposed to gun fire but otherwise gains the advantage of being able to support Imore weight in water. In the event the inflatable floor is used in its removable form, then it is obvious that the boat oor which forms a water-tight seal with the frame of the boat need not be as strong to support the weight ef occupants of the boat as it would have to be if the auxiliary floor were not used. It will also be seen that the said auxiliary floor is composed of a series of collapsible and inflated bulkheads which bulkheads are separated into separate groups having ne air cennections therebetween. Thus, the bulkheads provide an inatable raft, which may have one or more compartments or bulkheads punctured without completely losing the buoyancy of the raft.

It is to be understood that if desired the tubes a, b, c, d, e. f. g, h, i. i. k, l, m, n, o, p, a. r. s. t, u, and 'v may be built into a boat oor proper as by vul'canizing the floor ID to the attached floor of a boat or by any other manner found satisfactory. If the cellular floor is built as a permanent part of a boat it can not be used as a raft separate from the boat frame, but it will provide an additional number of air compartments to those usually `built into inflatable boat frames. More important the inflatable floor of the present invention provides air cells below the water surface whereby they are protected from shore gun fire. It is pointed out that the Hoor being below the water surface, a bullet cannot pass horizontally through the inflated tubes of the floor and thereby puncture all or a number of tubes. Also, that since the floor presents a relatively large surface to gun re from above, as from an airplane, and since the oor is divided into a number of separate inflatable groups of tubes, a bullet from above cannot puncture all of the air-sealed compartments. These features add greatly to the safety of applicants boat in combat. If desired, the said tubes composing the said inflatable floor may be made of a self-sealing type using any one of the several types of puncture-sealing tubes well known to the art. Additionally, closed-off compartments or inatable bulkheads may be obtained by running a transverse air-tight partition across each group of tubes and installing familiar .with the art. One such method is illus-- trated in connection with Fig. 1 by the dotted lines wherein the tubes b, c, d, e, f, g, h, i, i, lc,

Z, m, "n, o, p, q, r, s, t, and u are cut in two along the dotted line 32 shown in Fig. l and then the cut ends are sealed shut by a cover of cemented rubberized fabric or tape similar to that used for strip l5, after which the ends of the tubes are abutted thereby forming two sealed compartments in each of the last identied tubes.' Each compartment of each of the latter mentioned tubes has aligned communicating holes similar to the holes I! described above and accordingly the same type of bulkhead grouping. These additional bulkheads are served by pillow valves 23a, 24a, 25a and 26a. It will now be seen that applicant may divide his inflatable oor into many inflatable bulkheads which may be arranged in different positions relatively to each other.

Obviously the several features of the inven-- tion may be modiiied in several ways and the right is herein reserved tov make such changes as fall within the scope of the appended claim without departing from the spirit of the invention. l

I claim:

An inflatable boat oor of the class described comprising a plurality of elongated hollow members composed of rubberized fabric, said members being substantially rectangular in4 cross-section, some of said members being of different lengths and all being'arranged in side-by-side relation with the side walls of said members permanently joined in air-tight relation to the side wall of the next adjacent member, some of the partitions between said members having communicating holes therethrough whereby the assembled members are divided into separate groups between which there are no communicating holes, a top cover and a bottom cover attached directly to said members, each of said members having the walls of its end portions drawn together and folded backwardly, a reinforcing strip covering said folded portion, the reinforced folded end portion being tucked inwardly into the end portion of said hollow member, a folded strip ofsubstantially the width of the distance between the top and bottom covers when said hollow members are' inflated abutted against the outer edges of the inwardly turned member, said edge portions of the top and bottom covers being turned down and up respectively against said folded reinforcing strip, corner reinforcing strips extending along both the top and bottom edges formed by the turning of said covers against the said folded strip, an additional finishing and reinforcing strip covering substantially the peripherial edge of the assembly enumerated, inaton valves attached to the outer walls of the said separate groups whereby said groups may be inflated or deated, said covers and reinforcing being composed of vulcanized fabric and the composite assembly being firmly bound together by vulcanization` JOI-1N G. KREYER. 

